Effects of combined exposure to lead and cadmium on pituitary membrane of female rats.

The effects of combined exposure to lead and cadmium on pituitary membrane were studied. Adult female rats were treated intraperitoneally with either lead acetate and cadmium acetate alone or in combination at a dose of 0.05 mg/kg daily for 15 days. Both metals accumulated in the pituitary after the exposure. The membrane fluidity was decreased after the heavy-metal treatment. Among the three groups cadmium treatment showed more effect than did other treatments and the combined treatment showed intermediate values. Na(+)K(+)ATPase activity was decreased significantly by cadmium and combined treatments. The Schiff's base and inorganic peroxide levels were increased after the metal exposure. In conclusion, exposure to lead and cadmium caused accumulation of the metals in the pituitary and lowered the membrane fluidity, which may affect membrane function and cause alterations in receptor binding and secretory mechanism(s) of pituitary hormones. The combined treatment with metals produced intermediate results.